Carbureting device



Mar; 6; 1923.

L.v T. THURBER CARBURETING DEVICE Filed Julie 25, 1921 Y Rm QM ik N N QTwm NQ Q L Patented Mar. i6, 1923.

ina-ana LUMAN T. TEUR-BER, OF BROOKLINE, M ASSACHUSETTS, ASSIGNOB TO THEi/IANUFAC- TUBING ENGINEERS, INC., Il BROOKLINE, MASSACHUSETTS, ACORPORATION OF MASSACHUSETTS.

Application filed .Tune 23, 1921.

gaseous fuel mixtures and more particularly to an automaticallyadjustable auxiliary air port device applicable for use in operatinginternal combustion engines under variable load conditions, but theinvention is not limited thereto as it may be used generally withinternal combustion. engines where it is desired to obtain a variableauxiliary air supply under different conditions.

Objects of the invention are to produce an efficient fuel mixturethroughout varying load and to produce means for regulating the fuelmixture which is adjustable independently of the carburetor to controlthe fuel efficiency at various loads or to attain maximum efficiency, atany particular load, which produces more complete combustion, whichreduces the deposit of carbon in the engine, and which generallycompensates for improper mixtures produced by carburetors.

Other objects are to provide an auxiliary air intake device automatic inaction which is small7 compact and simple in construction andinexpensive to manufacture, which may be readily applied toi-enginesalready in use and be readily adjusted, and which has relatively fewparts so constructed and arranged as to be readily inspected, replacedor repaired.

The invention involves an auxiliary inlet device communicating` with theinlet manifold in advance of the throttle to vary the auxiliary airsupply in direct proportion to the throttle opening and in inverseproportion to the pressure in the manifold, `thereby to admit more airat higher loads and consequently to increase the fuel efficiency athigher loads when employing certain types of carburetors.

An example of the invention is shown for illustrative purposes in thedrawing hereto annexed, in which Fig. lis a diagrammatic view showingone application of thedevice applied to an'intake manifold between thethrottleand in- .f take' y.valve g, and

CARBURETING DEVICE.

Serial No. 479,806.

.Fig 2 is a longitudinal section of the device.

The device comprises in general a casing having a chamber adapted to beconnected with the intake manifold, preferably at a point between thethrottle and the intake valve of an internal combustion engine, whichchamberl is provided with air ports normally open to the atmosphere, anda means responsive to the varying vacuum in the passage of the manifoldsoas to automatically reduce or cutoff the air supply to the firstmentioned chamber under certain conditions, such for example as thoseexisting during relatively low loads when the throttle is more or lessentirely closed.

As shown in Fig. 2, the device comprises a tubular member 10 open atopposite ends 11, 12 thereof, and having a transverse wall or partition13 preferably arranged adjacent one end 12 so as to form a chamber 14-between said wall 13 and the open end 11. The wall of the chamber 14 isprovided with a series of apertures or air ports 15, said air portsbeing disposed adjacent to the transverse wall 13 and preferably beingdisposed longitudinally of the tube and also extending around theperiphery thereof. It is understood however, that the size, arrangementand disposition of th'e air ports may be varied as desired to meet theparticular conditions of use. Means are provided adjacent the end 11 forsecuring the device in position. rlhe outer surface of the tube isthreaded at 16 adjacent theend 11, and a shoulder 17 preferably formedas a nut, is arranged adjacent thereto so that a wrench may be used forscrewing the device in position. It is understood however, that othersuitable means may be employed for securing the device in position.

As shown in Fig. 2, a cap 18 is provided which telescopically fits orslides over the end 12 of the tube ,10, and forms a substantially closedchamber 19 which communi- Cates directly with the passage of the intakemanifold, so as to be subject to the partial vacuum therein. Preferably,a tubular rod 2O is provided for this purpose, which rod passes throughthe wall 13 and is xed in said wall, said rod having a passage 21therein which extends inwardly from the end thereof to a point beyondsaid wall. A port 22 connects 'the chamber 19 with the passage 21. A A;spring is interposed be- 110 air ports 15 are normally open. Preferably,

the rod 20 extends through thehead 24 of the cap, the projecting end 20of said rod` preferably being threaded and adapted to receive a nut 25which serves as an adjustable stop for limiting the outward movement ofthe cap 18. Another nut 26 is provided for holding the stop nut 25 inproper adjusted position. A spring 27 or other suitable yielding meansmay be interposed between the cap 24 and the stop 25 for cushioning theoutward movement of the cap 18.

The intakel manifold 28 is preferably passed through an exhaust manifold31 coming from lthe motor 32. Such an arrangement is of particularadvantage in using kerosen or other heavy fuel because the heat of ytheexhaust gases may be utilized to raise the temperature of the mixture inthe intake manifold and so facilitate vaporization of the fuel.

In operating the engine at relatively low loads, the throttle 30 will bealmost closed, and reciprocation of the pistons will produce a partialvacuum within the passage of the manifold. The partial vacuum formedtherein will be sufficient to overcome the action of the spring 23 andwill move the cap 18 inwardly upon the casing 10, so that the air ports15 will be closed by the cap 18, thus reducing the supply of air to themixture passing through the intake manifold from the carburetor 32. Itis to be noted that the auxiliary air supply is automatically variedinversely to the vacuum. This will enable a richer mixture tobe-provided at low loa-ds. However, as soon as the throttle 30 is openedat increasing loads, the vacuum will be reduced and the reduced vacuumwill permit the cap 18 to be moved outward, thus uncovering the airports 15 so as to furnish the additional air supply necessary to form anefiicient combustible mixture at the higher loads.

My improvement is not only useful in operating on heavy fuel, but I havefound that it improves the operation when operating with light fuelinasmuch as it varies the auxiliary air supply directly (i. e. notinversely) in proportion to the throttle opening.

I claim: 1. Ina device of the character described.

the combination of a tubular casing having a chamber with an air porttherein, a movable cap telescoping one end of the casing and adapted toclose tbeair port, a spring interposed between thecap and casing urgingsaid cap outward to normally maintain said air port open, and means forlimiting and cushioning the outward movement of thecap,sa`id meansincluding a'rod' xed to chamber.

the casing and extending through the cap, a stop on the rod outside ofthe cap and a spring on 'the rod between the capand the stop.

2. The combination with the intake manifold of an internal combusionengine of a casing having achamber with an air port therein, a secondcasing telescoping said first. casing and forming a chamber therewith,said second casing being relatively movable and jadapted to close theair port in the first casing, resilient means engaging said secondcasing to normally maintain the air port open, and a connectionbetweenthe second chamber and the intake manifold, said second chamber beingotherwise closed7 whereby a strong suction in the intake manifoldproduced when the "engine is being started or is running ata low speedautomatically causes the second casing to advance over the air port.

3. In a device of the character described the combination of a tubularcasing having a chamber, a normally open air port for the chamber formedin 'the side of the casing, a second relatively movable tubular casingtelescoping the first casing and forming a chamber therewith, a. spring'co-operating with the casings to maintain the air port normally open, alconnection from said sec- 95 ond chamber to a source of negativepressure, said second chamber being otherwise closed, whereby saidsecond casing is moved automatically and selectively to control theopening and closing of the air port inre- 100 sponse to variations inthe negative pressure.

4. In a device of the character described,

'the combination of a tubular casing having` a chamber, a normally openair port for the chamber formed in the side of the casing, a secondrelatively movable tubular casing tel-- escoping the first casing andforming a substantially closed chamber therewith. said chamberscommunicating independently 110 with with a source of negative pressure,said second casing being arranged to close the normally open air portupon formation of a vacuum in the closedchamber, and a spring within thesubstantially closed chamber interposed between the two casings so as tokeep the air port normally opembut to permit the air port to be closedupon the lformation of a vacuum in the substantially closed 120 5. In adevice of the character described, for attachment to the intake manifoldof an internal combustion engine, the combination of a casing having achamber adapted to be connected to an intake manifold, said chamberhaving an air port in the wall of the casing, a second casing movablerelative to the first casing and adapted to form a substantially closedchamber therewith, and to vary the air port of the first chamber, saidYsubstantially closed chamber having a port communicating directly withthe intake manifold and independently of the connection of the firstchamber thereto, and a spring interposed between the two casingsnormally holding the air port open, whereby upon formation of asufficient vacuum in the intake manifold the spring will be compressedto permit the air port in the first chamber to be reduced. n

6. An auxiliary air mixing device adapted to be connected to an intakemanifold comprising a casing having a plurality of relatively movableparts arranged to form a plurality of chambers, each of said chamberscommunicating by separate passageways with the intake manifold so as tobe subject to the vacuum therein, one of said chambers having air portstherein, and the other chamber having a movable portion associatedtherewith arranged to vary the air supply inversely to the pressure inthe manifold.

7. An auxiliary air mixing device adapted to be connected to an intakemanifold, comprisin a tubular member open at one end, a cap te escopingone end of said tubular member and adapted to form a substantiallyclosed chamber therewith, means arranged to form a passage between saidclosed chamber and the intake manifold, and resilient means interposedbetween the tubular member and cap, said tubular member having an airinlet port adapted to be varied by relative movement between the' capand the tubular member.

8. In a device of the character described the combination of acylindrical casing having a chamber with an air port there-in, saidchamber being open a one end and closed at the other, a movablecylindrical cap adapted to telescope said cylindrical casing to form asubstantially closed chamber with the closed end of the cylindricalcasing said cap being adapted to close the air port, a spring betweenthe cap and casing maintaining the air ports normally open, and a rodextending` axially through the casing and cap, said rod being fixed inthe head of the cylindrical casing and having a passage extending inwardfrom one end communicating with the substantially closed chamber, and astop on the other end adapted to limit the outward movement of the cap.

9. An auxiliary air mixing device adapted to be connected to an intakemanifold coniprising a fixed air chamber and a movable air chambertelescoping together, the fixed chamber communicating with the intakemanifold and having a plurality of air ports adapted to be closed by thetelescoping movement of the movable chamber, and lmeans connecting saidmovable chamber directly to the intake manifold so as to have a partialvacuum produced therein by suction of the engine thereby to telescopewith the fixed chamber to close one or more of said air ports.

10. An auxiliary air mixing device adapted to be connected to an intakemanifold comprising a fixed air chamber and a movable air chambertelescoping together, the fixed chamber communicating with the in.- takemanifold and having a plurality of air ports adapted to be closed by thetelescoping movement of the movable chamber, and a direct communicationbetween said movable chamber and the intake manifold comprising a hollowguide rod extending from the fixed chamberand forming a guide for themovable chamber in its telescoping movement with the fixed chamber.

ll. An auxiliary air mixing device adapted to be connected to an intakemanifold comprising a fixed air chamber and a movable air chambertelescoping together, the fixed chamber communicating with the intakemanifold and having a plurality of air ports adapted to be closed by thetelescoping movement of the lmovable chamber, and a hollow guide rodextending from the fixed chamber and forming a guide for the movablechamber in its telescoping movement with the fixed chamber, said movablechamber communicating directly with the intake manifold through saidrod, said rod extending beyond said movable chamber and having anadjustable stop thereon to limit the outward 'movement of the latter.

Signed by me at Boston. Massachusetts, this fifteenth day of June,'1.921.

LUMAN T. THURB ER.

